I've never been to Walnut Point but I have, unfortunately, experienced fishing like you described. Summer and, especially, late summer can be hard!
Hmmm...I'm trying to think of other lakes I've fished in the local area. Weldon Springs-early spring trip-couldn't catch a cold, A pond in Sibley (not to be confused with Sidney)-Not a very scenic pond but caught a few decent bass, Heritage lake on the old Chanute AFB grounds-pretty good in spring, not so good in summer. I've never been to Lake Vermillion (in or near Danville) so I won't provide comment.
Some lakes that are worth a drive if you have the time and/or gas money: Sanchris, Mill Creek, Kankakee River-has walleye, smallmouth, etc. Evergreen Lake (near Bloomington) (has sauger, bass, muskie, white bass, crappie)-but also requires a boat fee if you are out-of-district (which champaign is). There is another lake I'd share but I'd want to know what kind of fisherman you are first. Newton Lake is famous for big bass. Personally, somewhat ashamedly, in the three times I've been there, i didn't do that great.
Dawson Lake has walleye which is a bit of an exotic species for around here. (Well, Clinton has walleye too but you know how I feel about that lake-(bwell has heard me rage about that lake on many occassions). Dawson is not great for bass though, apparently, there are a few small tourney's on it each year. Given it's size, I am surprised it is fished as hard as it is. Perhaps it's because, while it has a no-wake restriction, boats are not limited to certain horsewpower motors and anyone can put on there.